Cultivator



J. SCHAEFFER Dec. 18, 1934.

CULTIVATOR Filed Sept. 28, 1952 INVENTOR.

9 ATTORNEYS Patented Dec. 18, 1934 a 1 UNITED STATES PATENT OFFICE-GULTIVATOR f John Schaefier, Horicon, Wisl, 'assignor to Van BruntManufacturing Company, Horicon, Wis., a corporation of Wisconsin 3 IApplication September 28, 1932, serial No. 635,158

' 11 Claims. (01; 91 m) This inventionrelates to cultivators and spesurethat'the standard will be returned to its cifical-ly provides animproved spring trip mechnormal position without stopping thecultivator. anism for field .cultivators and the like. Adjustment of ithe leverage of the spring on the I Cultivators. known to the art asfield cultivastandard when the standard is in its normal po- 15 tors,comprise a suitable framework ,to which sition-is accomplished by simplemeans, so that 5 beams or draw bars are pivotally attached. At thecultivator maybe readily adjusted for difthe free ends of these drawbars are mounted ferent soil conditions. i tool supporting standardswhich carry the earth My invention will be best understood byreferworking tools. These standards are pivotally ence totheaccompanying drawing in which a mounted upon the beams so that they'mayswing preferredembodiment of it is shown by wayof 10 rearwardly of thecultivator when the earth workexample and in which: ing tool engages anobstruction such as a rock Figure 1 is an'elevational view of acultivator or large root. beam and-standard, with the spring trip mecha-In cultivators of this class the tool supporting nism attached thereto;standards are usually held in their normal posi- Figure -2-is a planview of thedevice shown in 15 tion by-a spring acting through a systemof 'le- Figure 1;

vers connected to the standard and to the beam; Figure 3-is afragmentary view of the spring The tension of the spring biases thestandard trip mechanism drawn to an enlarged scale;

into its normal position with a definite pressure, Figure '4 is alongitudinal cross sectional view and the spring yields to permit thestandard to taken substantially along the line 4=4 of Figure 20 swingrearwardly when an obstruction is encoun- 2 looking in the direction ofthe arrows; and

tered. Figure 5' is-a fragmentary cross sectional view Preferably, thespring and lever connecting it taken along the line 55 of Figure 3looking in to the standard are arranged-so that the spring the directionof the arrows and drawn to an enwill restore the standard to-its. normalposition larged-scale.

25 as soon as theobstruction has been cleared. In Referring now to thedrawing in more detail, order to restore the standard to its normalp0si-' the cultivator'draw bar or beam 1 comprises subtion, the springand levers must be capable of stantially parallel members 2 and 3 spacedapart accelerating the earth engaging tool through the by suitablespacers 4 and 5 and held together by ground, particularly if this returnto normal bolts 6 extended through the members and spac- 30 movement isto bemade while thescultivator is ers. Members 2 and'3 are perforated at7 to in motion. 7 i receive suitable king pins by which the members Inthe devicesof the prior, art of which I am are pivotally attached-totheframework of the aware, the return to normal movement of the cultivator;Suitable devices, not shown, are sestandard cannot berelied upon,particularly when cured to the beam to lift the same by rotating it 5the forward motion of the cultivator is continued. about the king pin,when it is desired to disen- The spring trip mechanism of my inventionimgage the soil engaging tool from the ground. The proves upon the priorart devices by providing members 2 and 3 extend rearwardlytfrom the apositive return to normal movement of the framework and converge towardthe median line tool supporting standard and atthe same time of thebeamL'terminating in parallel portions 8. 40 permits low pressurebiasing of the standard in A tool supporting standard 9 snugly fitsbetween its normal position so that" it may begmoved out the beam ends'8 and is pivotally mounted therein of that position before :thecultivator is damaged. by a suitable bolt 10. "This bolt permitsswinging In its preferred form, the spring trip mechamovement "of thestandard forwardly and backnism of my invention includes a. springpermawardly of the beam, as will presently appear. 45 nently connectedbetween a. fixed length lever The standard carries a suitable soilworking tool and the cultivator beam, and a link connecting 9" which'issecurely fixed thereto.- the lever to the toolsupporting standard.The The spacing member 5 contains a centrally lolink is arranged to movewith respect to the lever catedannular re'cess'll in which is journaledone so'that the effective leverage of the spring upon; end of a-levermember 12. This lever 12 is pro- 50 the standard may be increasedsomewhat durvidedwithahook-like end 13 which is fitted in the ing thelatter portion of the movement of the recess 11 to pivotally attach thelever to the beam. standard out oiits normal position. By this A U-shapd cl vis la p 4 i fix d to the free arrangement-the leverage of thespring'on the end of the lever 12 by a suitable pivot pin 15.

standard is maintained sufficiently high to in- This clamp receives thehooked end 16 0 the 55 spring 1'7, the other end of this spring beingprovided with a hook 18 which is engaged with a yoke portion 19 of theforward one of the spacing members 4. The spacer is provided with bosses21 and 22 which define the side walls of the groove 11 and serve to holdthe lever centrally in the beam.

Bosses 21 and 22 and the members 2 and 3 of the beam together form apair of annular recesses around the spacer 5, in which links 23 and 24are disposed.

A second pair of links 25 and 26 are pivotally secured to the standard 9by a suitable pin 27 which is projected through one of a plurality ofholes 28 in each link. The links 25 and 26 extend forwardly of thestandard 9 and are disposed on opposite sides of the lever 12 andpivotally connected to the links 23 and 24- by a suitable pivot pin 29.Links 25 and 26 terminate on opposite sides of a roller 31 which isrotatably mounted therebetween by a suitable pin 30. Lever 12 isprovided with a centrally located generally triangular portion having astraight side 33 which extends radially outward from the pivotal axis ofthe spacer 5. Roller 31 engages this radial edge 33 and is movabletherealong, as will presently appear.

As will be seen in Figures 3 and 4, the tension of the spring acts uponthe lever 12 through clevis 1e and tends to rotate the lever 12 in aclockwise direction about the pivotal axis of the spacer 5. The tensionof the spring is transmitted through the roller 31 to the links 25 and26, and tends to move links 25 and 26 and the standard 9 in a clockwisedirection about their respective pivotal connections into theirrespective normal positions in which they are shown in Figures 1 and 3.

' As will be seen in Figure 3, this movement of the links and lever isarrested by the engagement of the links 25 and 26 with the bosses 21 and22, respectively. The pivot pin 29 is moved toward a straight lineextended through the axis of the pivot 27 and the axis of the bolt 6, bywhich the spacer 5 is secured in the beam, but the movement is stoppedbefore the pivots are aligned. The roller 31 engages the lever 12 at ornear the free end of the radial edge 33, and the force of spring 17acting against this roller tends to move the links 25 and 26 so as tobring the axis of pivot 29 into line with the axes of the other pivots.

The bosses 21 and 22 are preferably hexagonal in shape and are locatedeccentrically of the axis of the bolt 6. The normal positions of thelever and links can be altered by rotating the spacer 5 around theybolt6. An ordinary wrench may be engaged with either one of these bosses torotate the spacer, which is then looked against further rotation bytightening bolt 6.

As the cultivator'is moved forwardly, the soil engaging tool 9 places aforce on the standard 9 that tends to rotate that standard rearwardly ofthe cultivator, that is, in a counterclockwise direction about the axisof the pivot pin. Such a force places the links 25 and 26 in tension andplaces the links 23 and 24 in compression. The force also has acomponent tending to rotate the links 23 and 24. in a counterclockwisedirection about the axis of the bolt 6. The lever arm, through whichthis component of force acts, has length equal to the distance that theaxis of the pivot pin 29 is from the straight line drawn through theaxes of pivots 27 and 6. That is to say, the lever arm of this force isdirectly proportional to the amount of the misalignment of the pivotalconnections of the links and lever.

When the spacer 5 is rotated to bring into engagement with the links 25and 26 the faces of the bosses 21 and 22 which are located nearest tothe axis of the bolt 6, this lever arm is shortest and consequently theforce on the standard 9 required to overcome the tension of spring 17 ismaximum. Conversely, when the spacer 5 is rotated so as to bring intoengagement with the links 25 and 26 those faces of the bosses 21 and 22which are located farthest from the axis of the bolt 6, the pivotal axis29 is moved farther out of line and the lever arm is greatest, andconsequently a minimum force is required upon the standard to move thesame out of its normal position. Inasmuch as the bosses 21 and 22 arehexagonal, six different adjustments are possible, and these adjustmentshave been found to be sufficient to adapt the cultivator forsatisfactory operation under all soil conditions likely to beencountered, and separate adjustment of the tension of the spring 17 isnot required.

As will be readily understood by those skilled in the art, the leverarm, through which the tension of the spring acts to rotate the lever 12about its pivotal axis, is a maximum length when the axis of the leveris at right angles to the axis of the spring, and that lever armdecreases in length as the lever is moved to increase or decrease thisangle. When the lever 12 is in its normal position, in which it is shownin Figure 3,,the efiective length of this lever arm is small. When thelever 12 is in its normal position the roller 31 is engaged therewith ator near the free end of the radial edge 33, that is to say, the rolleris at or near its maximum distance from the axis of bolt 6. Through thisarrangement the spring is connected to the standard 9 by a'low leveragelinkage When the standard is in its normal position. Inasmuch as thefinal portion of movement of the links 25 and 26 into the position inwhich they are shown in Figure 3 produces but a small movement of thestandard 9, this decrease in the eifective leverage of the spring uponthe stand ard does not prevent the spring from moving the standard intoits normal position;

Movement of the standard 9 out of its normal position rotates links 23and 24 in a counterclockwise direction about the axis of bolt 6 to movethe pivot pin 29 counterclockwise thereabout. Inasmuch as the pivot pin29 is nearer to the axis of bolt 6 than the roller 31, this movementcauses the roller 31 to move inwardly along the straight edge 33, thatis to say, to move nearer to the axis of bolt 6. During this move-'ment, the lever arm of the spring 17 upon the lever 12 increases as thearm rotates until maximum effective leverage is obtained when the axesarenormal to each other, as hereinbefore pointed out, and decreasesslightly as movement of the lever 12 is continued. Thismovement isstopped by the clevis 14 striking against the under edges of links 25and 26, at which time the roller 31 is engaged'with the innermostend ofthe straight edge 33.

Normally, the standard 9 is disposed at substantially right angles tothe beam 1; pivotal axes 6, 27 and 29 are nearly in line; and a largeforce must be exerted on the standard to move it with respect to thebeam. When the soil engaging tool strikes an obstruction, sufficientforce may be exerted to move the standard. During the initial portion ofsuch movement, that is to say, during the first ten or twelve degrees ofmovement, the leverage of the spring on the standard decreases rapidly,due to the increase in misalignmentof the pivotal axes, and consequentlythe force required to move the standard is decreased. During theremainder of the movement, the links and levers function to check thisdecrease in effective leverage so that the force required tomove thestandard rearwardly remains substantially con.- stant, or may evenincrease slightly- At the time that the clevis 14 strikes links'25 and26 to arrest the movement of the standard, the angle between thebeam andstandard is approximately 120, which angle is sufficient to permit thetool to clear itself. As soon asthe obstruction is cleared, the springmoves the standard back into its normal position. As-hereinbeforepointed out, levers and 25 are eachprovided with a plurality of holes28. The normal positioncf the standard 9 and also the final rearwardposition of the same are varied by moving the pivot pin from one ofthese holes 28 to another. The pin is held in place by a cotter pin 27,or its equivalent, so that this adjustment may be easily made when it isnecessary to do so.

Having thus described my invention, what I consider new and desire tohave protected by Letters Patent is pointed out in the appended claims.

What is claimed is:

1. In a spring trip release mechanism for cultivators, a beam, a leverpivoted to the beam for arcuate movement with respect thereto, a springfixed between the free end of said lever and said beam, a standardpivoted to said beam, means pivotally connected to said standard andslidably engaging said lever whereby the lever arm through which-thepivotally connected means acts upon the lever may be varied, and meansfor shifting the pivotally connected means relative to the lever toalter the leverage of said spring on said standard as the standard ismoved rearwardly of the beam to enable the spring to restore thestandard to a normal position.

2. The combination of a beam, a tool supporting standard pivotallymounted upon said beam for swinging movement forwardly and rearwardlythereof, a spring fixed on said beam, means connecting said spring tosaid standard to hold the same in a normal position under fixed tension,said means including a lever member and a link member slidably engagedand movable with respect to each other whereby the lever arm throughwhich one of said members acts upon the other may be varied, and meansfor shifting said first member relative to said second member toincrease the effective leverage of said spring on said standard duringthe final portion of a movement of the standard rearwardly of the beam.

3. The combination of a beam, a shovel supporting standard pivotallyconnected to said beam, a lever, pivot means connecting one end of saidlever to said beam, a link connected to said beam by said pivot means, asecond link pivoted near its rearward end to said standard and pivoted,

near its forward end to said first link, a roller on the end of saidsecond link contacting said lever, said first link serving to shift theend of said second link, on which the roller is disposed, relative tosaid lever, and a spring connected between said beam and said lever. I

4. The combination of a beam, a tool carrying standard pivotallyconnected to said beam, a lever pivoted on the beam, a spring connectedto said beam and said lever, and link means connecting said lever tosaid standard, means on said link means engaging said lever, and meansfor moving said engagi means toward the pivotal connection of said leverto the beam, as said standard is rotated on its pivot rearwardly of saidbeam, whereby said spring is tensioned and the point of application; ofthe reaction of said link on said ond link, pivot means connecting saidsecond link to said standard and to said first link, said pivot meansbeing disposed substantially in line when said standard is in a normalposition with respect to said beam, a rollerbn said second link,-a leverpivoted to said beam and engaging said roller, said first linkbeingadaptedto swingabout its pivotal connection :with the beampto controlthe point of engagement of the roller with said lever, and a spring forforcing said lever against said roller to thereby hold said standard insaid normal position.

6. Ina cultivator, a beam, a lever pivotally connected to said beam, aspring fixed between the free end of said lever and said beam, a toolsupporting standard pivotally supported on said beam and adapted toswing rearwardly of the beam when the tool strikes an obstruction, meansconnected to said standard and engaging said lever, means forcontrolling said first means to cause the point of engagement of saidfirst means with said lever to move toward the pivotal connection'ofsaid lever to said beam as said standard swings rearwardly to compensatefor loss of leverage of said spring on said lever, whereby the springrestores the standard to a normal position when the obstruction iscleared.

7. In a cultivator, a beam, a lever pivotally connected to said beam, aspring fixed between said lever and said beam, a standard pivoted tosaid beam for swinging movement thereon, a pair of links pivoted to saidstandard and disposed on opposite sides of said lever, a roller betweensaid links at the free ends thereof, said roller engaging said lever,and means for causing said roller to move toward the pivotal axis ofsaid lever as said standard is swung rearwardly of said beam.

8. In a cultivator, a beam, a lever pivotally connected to said beam, aspring fixed between said lever and said beam, a standard pivoted tosaid beam for swinging movement thereon, a pair of links pivoted to saidstandard and disposed on opposite sides of said lever, a roller betweensaid links at the free ends thereof, a straight edge on said leverextending radially outward from the axis of the pivotal connection ofthe lever on the beam, said roller engaging said straight edge, meansfor causing said roller to move along said edge toward said pivotal axisas said standard is swung rearwardly of said beam, and means on saidlever adapted to engage said pair of links to limit the rearwardmovement of said standard.

9. In a cultivator, a beam, a lever pivotally connected to said beam, aspring fixed between said lever and said beam, a standard pivoted tosaid beam for swinging movement thereon, a pair of links pivoted to saidstandard and disposed on opposite sides of said lever, a roller betweensaid links at the free ends thereof, a straight edge on said leverextending radially outward from the axis of the pivotal connection ofthe lever on the beam, said roller engaging said straight edge, andmeans including a pair of links journaled for movement around saidpivotal axis and connected to said first links at a point between saidroller and said standard for causing said roller to move along said edgetoward said pivotal axis as said standard is swung rearwardly of saidbeam.

10. The combination with a pair of members pivotally connected forrelative swinging movement, of a link pivotally connected to one of saidmembers, a second link pivotally connected to said first link near thefree end thereof, pivot means for connecting the free end of said secondlink to the other one of said members, a roller mounted on said firstlink between the free end thereof and the pivotal connection of saidsecond link thereto, a lever journaled on said pivot means and engagingsaid roller, means tending to rotate said lever to bring the pivotalconnection between the links substantially into line with said pivotmeans and the pivotal connection between said first link and member, anda hexagonal bushing first link striking said bushing to limit themovement of said lever, said bushing being rotatable on said pivot meansto alter the limit position of said first link.

11. In a cultivator, a tool beam, a tool standard pivotally connectedtherewith, a pair of pivotally connected toggle links, one connectedwith the standard and the other connected with said beam, the pivotpoints of said links being so disposed that the links are in foldedrelation with said points substantially in line when said standard is inone position, a spring biased lever pivotally connected with said beam,and means carried by one of said links and engaging said lever, thepoint of contact therewith moving radially with respect to the pivot ofsaid lever as the standard is swung about its pivot.

JOHN SCI-IAEFFER.

